I've lived in OC for 7 years now. Mission Viejo is the furthest south I've lived and Tustin the furthest north. Most of my years have been in Irvine. What everyone has said thus far has been very accurate. Here are some points from my own unique experience:
* OC is ground zero if you love Asian women. Irvine, Garden Grove, Westminster and Costa Mesa have the biggest concentrations. I've always been physically attracted to Asian women and have seemed to carve out a niche for myself with Vietnamese women. Not sure how, but they seem to gravitate towards me and I them.
* If you come from a simple "salt of the earth" area of the country OC will leave you feeling fatigued and empty at times. If you do any online dating, regardless of which one, you will see endless photos of women in their little black dresses, on couches in upscale lounges and clubs, bragging about how they "love to travel" and many will list their international travel resumes on their profiles. There will also be an abundance of photos taken on corporate jets, yachts, luxury sedans (Bentley's, Maseratis, etc.).
* I don't do night game but Newport Beach, Laguna Beach and Costa Mesa are where it's at if you do. @PapayaTapper lives in Newport I believe and can chime in here.
* Irvine is a nice, impeccably clean, Stepford Wives type of town that's centrally located in OC. The Irvine Company has a monopoly on nearly all of the apartment communities and shopping centers in Irvine. Being in my 40s and not into the night game scene I enjoy Irvine as it's relatively quiet, clean and fairly diverse.
* If you choose to live in Irvine and can swing the high rent, check out the following apartment communities: The Village, The Park and Centerpointe. All three are within a block of each other and sit across the street from the Irvine Spectrum shopping center. It's a huge outdoor mall that is constantly expanding and has a large assortment of restaurant/bars and is really good for running first date game. About three years ago I lived at the village and was just learning game and attempting to run the first date bang recipe and I cleaned up there. The logistics are A++++++ as you can walk across the street to meet your date, have endless options for where to go and when you bring her back to your place have her drive you back
Every single woman I brought back LOVED where I lived. I could almost lipsync along when they, on cue recited "OMG It's like a resort here".
I also met a number of women when out solo at the mall. Weeknights are great for catching late night happy hours and I never had to worry about drinking and driving as home was a quick stagger across the street.
Long story short, if you're an above average looking white guy, on the taller side with good style, fitness and income you can KILL IT in OC, especially with the Asian women.